The most obvious change has come through the air, where quarterback Colin Kaepernick is playing at his highest level inside an attack that now has its top receiver back in the mix. The play of Michael Crabtree -- showing no visible lag from his Achilles injury -- made all the difference in Sunday's 23-20 wild-card win over the Packers in frigid Green Bay.

Crabtree's eight catches for 125 yards included receptions of 11, 12, 13, 14 and 31 yards, but nothing topped his clutch 17-yard grab in a third-and-10 scenario on San Francisco's final game-winning drive.

Crabtree's consistency in the elements impressed his coach, to say the least:

"In the northern snowlands, down to the tropics' sunny scenes, he's catching the football. Where they throw a football, he'll be catching it."

Harbaugh's poetry rings true. We don't interpret his praise as anointing Crabtree above, say, Jerry Rice. It's more a gushing over his ability to produce in any environment. It's also just Harbaugh being Harbaugh.

Crabtree was Kaepernick's favorite target last season and once again on Sunday. Kap targeted him 13 times Sunday, a season high -- and the equal of his throws to Anquan Boldin (six) and Vernon Davis (seven) combined.

Sunday represented a shift from the regular season, when Kaepernick's 21 touchdowns included 13 to Davis, seven to Boldin and just one to Crabtree, who played in just five games on his way back from offseason surgery.

"If my life depended on it and somebody had to catch a ball," Harbaugh said, "I'd enlist Michael Crabtree to do it."

Toss in San Francisco's eternally rugged ground game, and the Panthers -- playoff newbies -- have their hands full in what shapes up, on paper, as next weekend's finest game.